5.
Do we need to shard right now?
• Two schools of thought:
1. Shard at the outset to avoid technical debt later
2. Shard later to avoid complexity and overhead today
• Either way, shard before you need to!
– 256GB data size threshold published in documentation
– Chunk migrations can cause memory contention and disk
IO
Working
Set
Free
RAM
Things seemed fine…
Working
Set
Chunk
Migration
… then I waited
too long to
shard

11.
Storage model spreadsheet
sensors 16,000
years to keep data 6
docs per day 384,000
docs per year 140,160,000
docs total across all years 840,960,000
indexes per day 801248 bytes
storage per hour 63 MB
storage per day 1.5 GB
storage per year 539 GB
storage across all years 3,235 GB